1. Field of the Invention
The present invention relates to an apparatus and a method for performing printing on a sheet.
2. Description of the Related Art
Duplex printing is a printing apparatus feature that allows the automatic printing of a sheet on both sides. Japanese Patent Laid-Open No. 2008-126530 describes a printing apparatus that performs duplex printing on both sides of a long continuous roll sheet using an inkjet printing method.
When performing duplex printing, the apparatus described in Japanese Patent Laid-Open No. 2008-126530 performs printing on the front surface of a sheet and winds the sheet onto a winding roller, reverses the front and back surfaces of the sheet, and performs printing on the back surface of the sheet. If the ink is not sufficiently dried when the sheet is rolled, the ink undesirably is transferred to another portion of the rolled sheet. In addition, in the apparatus described in Japanese Patent Laid-Open No. 2008-126530, the printed sheet is cut page by page after the duplex printing is performed, and the cut sheet is output onto a tray. If the next cut sheet is output onto the sheet before the printed sheet is sufficiently dried, the ink undesirably is transferred to the sheet when the next sheet is topped on the sheet, or the drying of the sheet is further delayed. Accordingly, for the apparatus described in Japanese Patent Laid-Open No. 2008-126530, a sufficient period of time for naturally drying the ink is needed during a printing operation.
In a high volume printing market, such as print labs, it is required to increase the print throughput (the number of prints per unit time). One of the factors that prevents the print throughput from increasing is a long ink drying time after a print operation is performed. For the apparatus described in Japanese Patent Laid-Open No. 2008-126530, a sufficient period of time for naturally drying the ink is needed. This period of time prevents the print throughput from increasing. In particular, in a duplex printing operation, a large amount of ink is supplied to the front and back surfaces of the sheet. Therefore, if a natural drying process is used, it is difficult to increase the print throughput.